Elemental

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Rewind

Counter target spell. Untap up to four lands.

Island

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Sky Diamond

Crash Through

Creatures you control gain trample until end of turn. (Each of those creature can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Sprite Dragon

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on Sprite Dragon.

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Thousand-Year Storm

Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Warlord's Fury

Creatures you control gain first strike until end of turn.
Draw a card.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Sol Ring

Third Path Iconoclast

Whenever you cast a noncreature spell, create a 1/1 colorless Soldier artifact creature token.

Serum Visions

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Firemind's Research

Whenever you cast an instant or sorcery spell, put a charge counter on Firemind's Research.
{1}{U}, Remove two charge counters from Firemind's Research: Draw a card.
{1}{R}, Remove five charge counters from Firemind's Research: It deals 5 damage to any target.

Wee Dragonauts

Flying
Whenever you cast an instant or sorcery spell, Wee Dragonauts gets +2/+0 until end of turn.

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Ferrous Lake

Battle Hymn

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Mountain

Bria, Riptide Rogue

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Other creatures you control have prowess. (If a creature has multiple instances of prowess, each triggers separately.)
Whenever you cast a noncreature spell, target creature you control can't be blocked this turn.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Electrostatic Infantry

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Electrostatic Infantry.

Lavaspur Boots

Equipped creature gets +1/+0 and has haste and ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {1}

Saheeli, Sublime Artificer

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
−2: Target artifact you control becomes a copy of another target artifact or creature you control until end of turn, except it's an artifact in addition to its other types.

Soldier

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Arcane Signet

Arcane Bombardment

Whenever you cast your first instant or sorcery spell each turn, exile an instant or sorcery card at random from your graveyard. Then copy each card exiled with Arcane Bombardment. You may cast any number of the copies without paying their mana costs.

Blow Off Steam

Blow Off Steam deals 1 damage to any target. (Then exile this card. You may cast the creature later from exile.)

Frolicking Familiar

Flying
Whenever you cast an instant or sorcery spell, Frolicking Familiar gets +1/+1 until end of turn.

Frolicking Familiar // Blow Off Steam

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Burning Prophet

Whenever you cast a noncreature spell, Burning Prophet gets +1/+0 until end of turn, then scry 1.

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters tapped.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Academy Elite

Academy Elite enters with X +1/+1 counters on it, where X is the number of instant and sorcery cards in all graveyards.
{2}{U}, Remove a +1/+1 counter from Academy Elite: Draw a card, then discard a card.

Drake

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Izzet Signet

Gitaxian Spellstalker

Trample, ward {2}, prowess, prowess (Each instance of prowess triggers separately.)

Khenra Spellspear

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{3}{U/P}: Transform Khenra Spellspear. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Khenra Spellspear // Gitaxian Spellstalker

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Reliquary Tower

Bird Illusion

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Servo

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Counterspell

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Stormchaser Mage

Flying, haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.